This invention relates generally to electrical feedthroughs and, more particularly, to an hermetically sealed coaxial cable feedthrough.
Hermetically-sealed casings are used extensively to package a variety of hybrid microcircuits. Typically, glass-to-metal seals are employed to hermetically seal and electrically isolate one or more lead wires from a package body. Generally, the hermetic seal is produced by fusing glass between the lead wire and the package body. Such hybrid packages provide, for microelectronic circuits, enclosures that are electrically accessible but completely isolated from external hostile environments.
Significant problems encountered during the creation of hermetically sealed packages stem from requirements for internal circuitry routing. The use of either elongated pin feedthroughs or gold ribbons to reach internal circuitry often results in impedance mismatches. Conversely, the interconnection of internal circuitry and feedthrough pins with coaxial cable assemblies entails sensitive soldering procedures that can damage individual components, particularly the fragile inner conductors of the cable assemblies.
The object of this invention, therefore, is to provide an improved feedthrough for hermetically sealed packages.